TUCSON, Ariz. -- The Diamondbacks are moving closer to getting back key pieces of their offense and starting rotation.

Veteran outfielder Eric Byrnes and left-hander Doug Davis went through encouraging morning workouts on Friday at the team's Spring Training facility at Tucson Electric Park.

Byrnes, recovering from last year's severely torn left hamstring, ran the bases at the Minor League complex prior to Friday's Cactus League game against the Mariners, and came through the session with flying colors.

"He ran well," manager Bob Melvin said. "He's getting better every day. It's by the far the best I have seen him run. If all goes well, he will take [Saturday] off, [we'll] get him in a Minor League game on Sunday and have him back with us Monday or Tuesday."

The news was equally promising with Davis, who tossed a bullpen session.

"He threw all of his pitches and seemed to be fine," D-backs pitching coach Bryan Price said. "He seems to be getting better each time out."

Davis, who had a 6-8 record and a 4.32 ERA in 26 starts last season, missed his most recent Cactus League start after experiencing pain in the triceps area of his left arm.

His session on Friday consisted of throwing several pitches, sitting down for a few minutes, and throwing again.

Melvin said Davis would take Saturday off, throw again on Sunday, take two days off and pitch in the Wednesday home game against the Brewers.

"I think [Saturday] will tell us a lot on how he bounces back," Price said. "Hopefully, he will be fine and can proceed towards his intended start against Milwaukee."

Melvin added that Davis would throw about 40 pitches against the Brewers, and if all goes well the remainder of Spring Training, he would have plenty of time to get ready for the regular season.

"If he pitches on the 18th, he would get four starts and be ready," Melvin said.

Right-hander Max Scherzer, sidelined with shoulder inflammation, was scheduled to face hitters on Friday and Melvin said the pitcher was getting "pretty close" to returning to action.

"I don't know the exact day," said Melvin. "A lot of it has to do with how he feels the next day after he throws to hitters, so we'll probably have a date for you [on Saturday]."

Prior to Friday's game, the D-backs announced that they have reassigned right-handed pitchers Hector Ambriz, Tony Barnette, Brooks Brown and catcher Ed Easley to Minor League camp, leaving 54 players vying for Opening Day roster spots.